Machine for treating paper mill waste



March 16,1954 1: FRASER 2,672,075

MACHINE FOR TREATING PAPER MILL WASTE Filed Feb. 20, 1950 2 Sheets-Sheetl Inventor @00 /a 5 2/7Se/ Attorney March 16, 1954 FRASER MACHINE FORTREATING PAPER MILL WASTE 2 Sheets-Sheet 2 Filed Feb. 20, 1950 I rwentoravj/ir f l dfff" w/m Afiorney 7 plates.

- less bulky dimensions.

Patented Mar. 16, 1954,

MACHINE FOR TREATING PAPER MILL WASTE Douglas Fraser, Moi-den, EnglandApplication February 20, 1950, Serial No. 145,127

Claims priority, application Great Britain March 23, 1949 4 Claims. 1

This invention relates to an improved machine for treating paper millwaste including brokepaper or esparto grass or straw or the like and hasfor its object in the case of the first named material, means forreturning into pulp stock the made or partly-made paper, common known asbroke-paper, and of effectively treating the other waste material thatoccurs in the various stages of paper manufacture and reducing same alsoto pulp stock. The broke-paper may be in a partly prepared condition orotherwise and is normally collected by hand and trucked or conveyed awayfor re-pulping.

Esparto grass is normally put through a machine generally known as aduster to remove sand, dirt, etc. and is then conveyed away for furthertreatment. In this invention the esparto grass can be fed into thereceiving vessel which forms an integral part of the apparatus and canbe washed free of sand and dirt. This method of treatment obviates theuse of a duster machine and a dust-collecting apparatus with itspotential fire danger in the mill. This fire danger is due to the finedust and "flufP which fills the surrounding air during the working ofthe duster machine and which renders the air and any place where dustsettled highly inflammable.

According to the present invention, immediate- 1y a charge has been fedinto the treatment vessel it is wetted with water thereby eliminatingall fire risks and in the course of its treatment such raw material asesparto grass or straw is reduced whilst in a wet state to parts ofsmall dimensions by a preliminary tearing process, and then passes underimpellers placed above perforate rubbing The pulp produced is thenseparated from any admixed dust or grit, and can pass to paper pulprefining units for further treatment.

Straw is normally similarly dusted and then chopped by a cutter intomore manageable and A dust-collecting apparatus is normally a feature ofsuch a process and the potential fire danger obtains. By the use of thisinvention the straw can be immediately wetted and the dust laid. Theimpeller aforesaid reduces straw and straw-like material into smalldimensional sizes thus obviating the use of any preliminary cuttingoperation.

The object of the present invention is to provide an apparatus that willreadily receive or actually induct broke-paper and likepaper mill wasteor esparto grass, straw or. the like and consists of a chest or tankcontaining revolvingarms,

' stationary tearers, an attrition impeller or impellers, an adjustableparticle size classifier, and

a wet grit trap and separator. V p

The invention consists in an improved machine for treating paper millwaste and comprises in combination a receiving vessel with water supplythereto and pulp inlet thereto and exit therefrom, a driven verticalshaft centrally disposed in said vessel, drag arms fast on said shaft,tearer brackets fast with the internal peripheral walls of said vesselco-operating with said drag arms, horizontal impellers fast with thelower portion of said central shaft, grooved perforate rubbing platesforming a foraminous partition in said vessel below said impellers,means for adjusting one said perforate plate in relation to the otherand means for eliminating sand grit below said partition to exit.

The angular relationship of the drag arms with the tearer brackets issuch as to provide a shearing action to any pulp or paper stock comingtherebetween and both of these parts may be fitted with renewable edgeparts to compensate for operative abrasion.

Further, the impellers are formed with concave faces in the direction ofdrive and since these impellers rotate over the grooved perforate platesproducing a secondary shearing action the pulp stock, which is forcedinto the cavities of the curved impellers, is curled over again andagain to be sheared against the ridges or groove edges of the upperforaminous plate. 7

Conveniently the above machine is erected to feed a paper pulp refiningmachine with means for recirculating the partly refined paper stock tothe receiving vessel either above or below th drag arms aforesaid.

In order to eliminate sand grit and other like matter of small particlesize from the wet paper pulp stock resulting from the macerationprocess, it is necessary to provide means to segregate this materialfrom the flow of pulp and eject same as waste. To this end a wet grittrap is arranged below the foraminous plates. This consists of a conicalor roof shed structure with an annular launder covered with gauze overwhich the raw pulped paper stock is compelled to fiow after its passagethrough the perforated plates. Preferably this gauze cover is formedwith a shallow annular depression coincident with the 3 to circulatethrough the mass at such point and thus assist in the elutriation of thegrit and its passage to exit.

To those conversant with paper making it will be obvious that'the abovedevice may take various forms mainly dependent upon the type of paperwaste to be treated with accentuation of some of its features orotherwise, but in order that the invention shall be more fullyunderstood reference is made to the accompanying drawings wherein thereis illustrated a type of machine that may be called upon to deal withtheoverall waste of a modern factory, as a preferred embodiment andwherein:

Fig. l is a part sectional elevation of the invention shown as mountedin flow with a cone type paper refining machine.

Fig. 2 is a sectional plan on line A-A Fig. 1.

Fig. 3 is a part sectional plan on line BB, Fig. 1.

Fig. '4 is a cross section of the rubbing plate.

Fig. .5 is a fragmentary plan of upper rubbing plate.

Referring to the drawings and to Fig. '1 the receiving vessel "D is"formed with a circular body I, a cover i2,-a truncated conical lowerpart 3, a foraminous.partitionreferred'to as a whole under 4, and abase'bowl 5. The cover has an opening '5 for the admission of paperwaste, said cover carries a gear box 1 with means for driving adependent central shaft/3. The gear in box I is driven by an electricmotor 8 or any substituted source of power by means of a shaft it andcoupling l l. The shaftB carries a series of drag arms mounted onsleeves i 3.fastiwith the shaft 3.

The said arms I2 are adapted to co-operate with the tearer brackets "M,the latter being formed as shown'and mounted fast cn'theinner peripheryof the vessel body '5. The said arms t2 and brackets M are not in radialalignment, the lack of coincidence 'beingafew degrees, as .see'Fig. -2,so that the arms 82 drag the waste paper along a shearing edge en thebrackets M1. The edges of thebrackets it maybe serratedor straight andin some cases are faced with toughened or hardened steel to resist wear.

The sha-ftfi may be of the suspended type as shown in Fig. l or may beguided'initsilength by passing through abracket Win the vessel part 3 asshown in dotted lines. At the "lower part of the shaft 8 ismounted'iiast therewith an impeller it having several arms of paraboloid,or cup secin Fig. 3 the coincidence or otherwise of the perforations 18in the plates 4a and 4b can be adjusted by manipulating wheel 23 to givea series of maximum openings to practically nil.

Below the partition J ,is mounted a facially grooved support 2'!having'a gritlaunder 28 connected to waste pipe 29; over the support 21is laid a. wire fabric 30 having any desired mesh opening-dimension. Themesh covering lies upon its iacially grooved support, and is then inbentat 31 to follow the curvature of the launder 28. The meshing 30 isspaced away from the launder lip so that fine paper pulp passing throughthe mesh is caused to overflow the edges and rejoin the main body ofpulp in the vessel base 5.

The device as shown in Fig. 1 is mounted so as to feed a paper pulprefining unit E. This unit E is of a known type pressure fed from acentrifugal pump 32. The outlet 33 is branched andbothbranchescontrolledbyvalves 3 and respectively. Valve 35 permits the refined pulp stock tobe sent'to a poaeher'chest or other part of the paper making plant, thevalve 35 being closed, or if valve 34is closed, the pulp is recirculatedthrough the vessel D again through the pipe "-36. Pipe 35 may also beused -f0r-sup-plying water to "the broke'paper or-may be inserted byconduit B'ientering the cover. Pulp'rnay-be withdrawn 'irom thecompartment 3 of vessel D through orifice "3B and pumped back to the topof the'vessel D.

In operation the paper mill waste, including broke paper, cuttings,trimmings, loose'raw paper stock including straw, esparto or other grassis introduced to the vessel D through the cover opening 6 and water issprayedin. The raw material is engaged by the drag arms 12 which intheir rotary motion andinclination induce the entry of material which isstripped away and teased by engagement of the arms l2 with the tearerbrackets 44 =fast withthe vessel part 1. Several arms l-2 may be fittedtoany one sleeve 1 3 and several 'tearer brackets-may be common to anyone-tier of sleeves. The broke material torn tion indicated at Na inFigure .1 and adapted-to rotate horizontally over the upper 'foraminousstatic partition plate 4a in the direction of the arrow seen inFigure 3.

The plate dca'see Fig. 4,.isformed with a series of sharp edged grooves"H with perforations I8 'overthe whole of the plate in the grooverecesses.

A single foraminous plate may be employed if the waste paper material isuniform, but with a view of providing an adjustment of plate orificebeneath the upper plate 4a there is a lower perforated plate to. Theplate 4b is formed with perforationsof identical pitch in bothdimensionswith those of .the upper plate 4a. Plate 42) is capable of relativemovement in relation to plate 4a. This is arranged as shown in :Fig. 1.The lower plate 41) is provided with a bracket 29 accommodating the head2| of a spindle 22 said spindle being threaded into a-nut 23. Shaft 22is prolonged to appear externally'and isprovided with a hand wheel orlever 25. "The nut 23 ,is

'madefastwith an entry sleeve 2,5.and the shaft "made tight againstleakage by cap 28. 'As shown off the uppermost arm -12 drops to the armor arms of the next tier. Centrifugal force tends to keep the brokepaper away from the central shaft and withwet'paperits'path'along thearms 12 is lubricated so that the bulk of the broke material entering-isengaged by and macerated upon the tearers l4. When the half formed paperpulp reaches section 3 of vessel D it falls upon the partition 4 wherethe raw pulp is dragged round over the sharp edges of the grooved plate4a by the impellers It. The paraboloid type of section of these impellerblades tends to cause the-pulp to engage and reengage the surface'oftheplatedmand when the predetermined fibre size has been attained, theparticles pass through the coincident or partly coincident perforationsand fall upon the grit catcher below, the 1 pulp traversing the meshfabric under water-flow down the incline into the depression 3i whereanyremaining grit sepa rates'andpasses-to'the launder below and is removedfrom the "vesselthrough ,pipe 29. In the passage of the pulp"overthe'mesh fabric anygrit or sand present passes through the openingsin the wire meshdown the-surfacegrooves cutin' the face 'of 'the supportand are washed into the launder andpassto waste. 'When'the pulppassesthegrit meshing 3i! "it'overfiowsthe'launder and passes to the. refiner'If the vessel D ,is not keeping pace WithQinputppthe broke paper .ishard or caked, the apertures in the foraminous partition are widened tomake the openings in the plates 4a and 4b more coincident bymanipulating the handwheel 24, this arrangement being of the push-pulltype whereby aperture size can be adjusted with a single control. Withthis arrangement the coarse ulp is fed to the refiner D and isrecirculated in the treatment vessel until the desired texture of pulpis obtained.

I claim:

1. In a machine for treating paper mill waste to reduce same to pulpstock, the combination of a treatment vessel, a horizontal partitioninsaid vessel defining an upper chamber and a lower chamber, saidpartition being perforate, a shaft extending vertically in said upperchamber, drag arms radiating from said shaft, tearer brackets on theinside of the vessel in its said upper chamber portion, said chamberportion having inlet means for the introduction of the mill waste and asupply of water, horizontal impeller means on said shaft in closeproximity to said perforate partition and within said upper compartment,means for rotating said shaft to rotate said drag arms and said impellermeans, said drag arms and tearer brackets cooperating to tear andinitially macerate said mill waste in the said upper chamber, saidimpeller means operating at the bottom of the upper compartment to pulpthe macerated waste and discharge same into the lower chamber throughthe perforate partition, said impeller means being formed to churn themacerated mill waste upon said perforate partition, a grit screeningdevice in said lower chamber immediately beneath said perforate screenand in the path of the discharge of the pulp particles from saidperforate partition, said device serving to separate grit from the pulpparticles, a discharge outlet in said lower compartment for thedischarge of the pulp and a discharge outlet on said grit screeningdevice for discharging the separated grit.

2. I he invention as defined in claim 1, said perforate partitionincluding separate perforate plates mounted in surface contact with oneanother with their respective perforations in register, and means foradjusting one said plate relatively to the other to vary the effectivesize of said registered perforations.

3. The invention as defined in claim 2, said impeller means comprisingradiating arm members of cup-shape section.

l. An improved machine for treating paper mill waste of the type setforth having means for macerating partly formed paper pulp comprising arotary impeller disposed above a foraminous grooved upper rubbing plate,said grooves having parallel sides and upper shearing edges,perforations within said grooves, said upper plate being static andconstituting a base to the macerating vessel, a perforate lower platemobile under control in relation to said upper plate for total orificeadjustment, a grit catching device disposed below the foraminous plates,said device comprising a launder mounted below said rubbing plate, agrooved cone or shed disposed within said launder having serrated outeredges, the said cone or shed being provided over its entire superficialarea with a covering of wire mesh or gauze, the latter being inbent atthe launder edge and passing therefrom, apron fashion, to cause the pulpto overflow said edge and pass into the lower base of the vessel, thelaunder passing any sand or grit caught in the grooves to a waste pipeand thereby ejected from the vessel as waste.

DOUGLAS FRASER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 785,025 Sherwood Mar. 14, 1905 879,440 Carothers Feb. 18, 19081,039,941 Herz Oct. 1, 1912 1,287,439 Richmond Dec. 10, 1918 1,515,336Brandt Nov. 11, 1924 1,556,926 Fritz Oct. 13, 1925 2,294,060 Wiener Aug.25, 1942 2,424,726 Wells July 29, 1947 FOREIGN PATENTS Number CountryDate 313,611 Great Britain Aug. 21, 1930 653,505 Germany Nov. 11, 1937

